The present invention relates to a device transferring system, a device transferring method, and a display manufacturing method such that correction of parallelism between substrates is easy to achieve, in a technology wherein devices bonded to an adhesive layer formed on a first substrate are transferred from the first substrate side to the side of a second substrate by embedding the devices in an uncured resin layer formed on the second substrate.
There has been known a technology wherein devices bonded to an adhesive layer formed on a first substrate are transferred from the first substrate side to the side of a second substrate by embedding the devices in an adhesive layer (for example, an uncured resin layer) formed on the second substrate (see, for example, Japanese Patent Laid-open No. 2004-273596 and No. 2004-281630). In the embedding transfer technology, the first substrate and the second substrate are set as parallel as possible to each other, the first and second substrates are made to approach each other while maintaining the parallel condition, and only the devices on the first substrate are brought into uniform contact with the resin layer formed on the second substrate, whereby the devices are transferred from the first substrate side to the second substrate side.
In this case, if the first and second substrates make direct contact with each other due to such reason as bad parallelism between the first and second substrates, the adhesive layer on the first substrate and the adhesive layer on the second substrate would stick to each other, making it difficult to separate the first and second substrates from each other. If the first and second substrates in this condition are forcibly separated from each other, the adhesive layer on the second substrate would be damaged, resulting in a conspicuously bad transfer quality.
Therefore, in the embedding transfer, the accuracy in correction of parallelism for making the first substrate and the second substrate parallel to each other is important.
As a method for correction of parallelism between two substrates, there has hitherto been adopted a method in which the substrates are directly mechanically pressed against each other so as to cause the substrate on one side to accord to the substrate on the other side, or a method in which the two substrates are pressed toward each other in the condition where spherical spacers with a very high dimensional accuracy are clamped between the substrates (see, for example, Bond Aligner BA6 [online], 2002, Suss MicroTec K.K., Home page, Site map, Introduction of products, Substrate bonder/aligner, BA6 Bond Aligner, [searched on Mar. 31, 2005], Internet <URL: http://www.sussjp/html/ba6.html/>; and Suss MicroTec K.K. (formerly Karl Suss Japan K.K.) “Substrate Bonder/Aligner, BA6 Bond Aligner Pamphlet”, 2002). However, the direct pressing method is inappropriate, as has been mentioned above. In addition, the method of pressing the substrates toward each other with the spherical spacers clamped therebetween is also inappropriate, since the place for inserting the spacers is not secured in the case where the transfer area on the second substrate is greater as compared with the first substrate.